The reason Chansley refused to eat, he said, was because food which is not organic is against his beliefs and makes him physically ill.
This is the second time he has refused to eat in prison.
He was recently transferred from a Phoenix prison to Washington DC, where he refused to eat for four days.
He only ate once an Arizona judge ordered the jail to accommodate his needs.
Three weeks ago, when he was jailed in Arizona on charges stemming from the January 6 riot, Chansley went days without eating because the detention facility there didn't offer organic food.
The US Marshals Service in Arizona said it "reached an appropriate course of action regarding the dietary needs of Jacob Chansley" but declined to say whether he had been given organic food.
However, this time in the country's capital officials refused to accommodate Chansley's food needs.
In an email from officials to his lawyers they stated he "failed to identify a 'faith/belief' upon entering DOC's custody" and DOC's Religious Services staff were "unable to find any religious merit pertaining to organic food or diet for shamanism practitioner".
In his request to officials, he claimed he has eaten strictly organic food for the past eight years and to be served organic canned vegetables or soups, also writing that he hadn't eaten since January 2 before he was transferred to the new prison.
"As a spiritual man, I don't mind fasting," Chansley wrote, adding that the longest he's fasted previously was five days.
- Additional reporting by AP
